diff --git a/go.mod b/go.mod
index c6d878b..886d213 100644
--- a/go.mod
+++ b/go.mod
@@ -9,10 +9,12 @@ require (
 	github.com/gen2brain/jpegxl v0.4.5
 	github.com/gen2brain/webp v0.5.5
 	github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646
+	github.com/sergeymakinen/go-ico v1.0.0-beta.0
 	golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8
 )
 
 require (
 	github.com/ebitengine/purego v0.8.3 // indirect
+	github.com/sergeymakinen/go-bmp v1.0.0 // indirect
 	github.com/tetratelabs/wazero v1.9.0 // indirect
 )
diff --git a/go.sum b/go.sum
index 32f245f..3132db6 100644
--- a/go.sum
+++ b/go.sum
@@ -12,6 +12,10 @@ github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646 h1:zYyBkD/k9seD2A7fsi6
 github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646/go.mod h1:jpp1/29i3P1S/RLdc7JQKbRpFeM1dOBd8T9ki5s+AY8=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/sergeymakinen/go-bmp v1.0.0 h1:SdGTzp9WvCV0A1V0mBeaS7kQAwNLdVJbmHlqNWq0R+M=
+github.com/sergeymakinen/go-bmp v1.0.0/go.mod h1:/mxlAQZRLxSvJFNIEGGLBE/m40f3ZnUifpgVDlcUIEY=
+github.com/sergeymakinen/go-ico v1.0.0-beta.0 h1:m5qKH7uPKLdrygMWxbamVn+tl2HfiA3K6MFJw4GfZvQ=
+github.com/sergeymakinen/go-ico v1.0.0-beta.0/go.mod h1:wQ47mTczswBO5F0NoDt7O0IXgnV4Xy3ojrroMQzyhUk=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/tetratelabs/wazero v1.9.0 h1:IcZ56OuxrtaEz8UYNRHBrUa9bYeX9oVY93KspZZBf/I=
diff --git a/internal/builtins/ico.go b/internal/builtins/ico.go
new file mode 100644
index 0000000..fbe8b54
--- /dev/null
+++ b/internal/builtins/ico.go
@@ -0,0 +1,8 @@
+//go:build ico || core || full
+// +build ico core full
+
+package builtins
+
+import (
+	_ "github.com/coalaura/ffwebp/internal/codec/ico"
+)
diff --git a/internal/codec/ico/ico.go b/internal/codec/ico/ico.go
new file mode 100644
index 0000000..2a0f64e
--- /dev/null
+++ b/internal/codec/ico/ico.go
@@ -0,0 +1,80 @@
+package ico
+
+import (
+	"bytes"
+	"image"
+	"io"
+
+	"github.com/sergeymakinen/go-ico"
+
+	"github.com/coalaura/ffwebp/internal/codec"
+	"github.com/coalaura/ffwebp/internal/opts"
+	"github.com/urfave/cli/v3"
+)
+
+func init() {
+	codec.Register(impl{})
+}
+
+type impl struct{}
+
+func (impl) String() string {
+	return "ico"
+}
+
+func (impl) Extensions() []string {
+	return []string{"ico", "cur"}
+}
+
+func (impl) Flags(flags []cli.Flag) []cli.Flag {
+	return flags
+}
+
+func (impl) Sniff(reader io.ReaderAt) (int, []byte, error) {
+	magicICO := []byte{0x00, 0x00, 0x01, 0x00}
+	magicCUR := []byte{0x00, 0x00, 0x02, 0x00}
+
+	buf := make([]byte, 4)
+
+	if _, err := reader.ReadAt(buf, 0); err != nil {
+		return 0, nil, err
+	}
+
+	if bytes.Equal(buf, magicICO) || bytes.Equal(buf, magicCUR) {
+		return 100, buf, nil
+	}
+
+	return 0, nil, nil
+}
+
+func (impl) Decode(r io.Reader) (image.Image, error) {
+	images, err := ico.DecodeAll(r)
+	if err != nil {
+		return nil, err
+	}
+
+	var (
+		best     image.Image
+		bestArea int
+	)
+
+	for _, img := range images {
+		bounds := img.Bounds()
+		area := bounds.Dx() * bounds.Dy()
+
+		if area > bestArea {
+			best = img
+			bestArea = area
+		}
+	}
+
+	if best == nil {
+		return nil, io.EOF
+	}
+
+	return best, nil
+}
+
+func (impl) Encode(w io.Writer, img image.Image, _ opts.Common) error {
+	return ico.Encode(w, img)
+}